Exhaust system for multi-rotor type rotary internal combustion engine

ABSTRACT

A rotary internal combustion engine of the multi-rotor type having a plurality of rotor chambers including exhaust chambers provided with exhaust ports respectively. The rotary internal combustion engine has an exhaust system constituted by exhaust passageways formed to be congregated in one portion of a rotor housing and communicating with the exhaust ports leading from the respective rotor exhaust chambers, and at least one exhaust manifold connected at one portion of the rotor housing to the exhaust passageways.

Otsubo et al.

[ Dec. 11, 1973 EXHAUST SYSTEM FOR MULTI-ROTOR TYPE ROTARY INTERNALCOMBUSTION ENGINE [75] Inventors: Kizuki Otsubo; Yoshikazu lshikawa,

both of Tokyo, Japan [73] Assignee: Nissan Motor Company Limited,

Yokohama City, Japan 221 Filed: Aug. 31,1972

21 Appl. No.: 285,349

[30] Foreign Application Priority Data Primary ExaminerCarlton R. CroyleAssistant Examiner-Michael Koczo, Jr. Attorney-John Lezdey et al.

[57] ABSTRACT A rotary internal combustion engine of the multi-rotortype having a plurality of rotor chambers including exhaust chambersprovided with exhaust ports respectively. The rotary internal combustionengine has an exhaust system constituted by exhaust passageways Sept. 1,1971 Japan 46/78926 formed to be congregated in one portion of a rotor52 us. Cl. 123/s.07, 60/323 housing and communicating with the exhaustports 511 int. Cl. .jrozn 53/04 leading from the respective rotorexhaust chambers, 58 Field of Search 123/807, 8.01, 8.45; at least one@Xhaust manifold connected at one 60/323 portion of the rotor housing tothe exhaust passage- I ways.

[56] References Cited UNITED STATES PATENTS 3 Claims, 5 Drawing Figures3,476,092 11/1969 Yamamoto 123/807 X EXHAUST SYSTEM FOR MULTH-ROTOR TYPEROTARY INTERNAL COMBUSTION ENGINE This invention relates to rotaryinternal combustion engines and, more particularly, to an exhaust systemfor a multi-rotor type rotary internal combustion engine.

'In a conventional rotary internal combustion engine of theabove-described type, it is a common practice to have rotor exhaustchambers provided with exhaust ports which are separately connected toexhaust manifolds leading to exhaust pipes, respectively. With thisarrangement, eachof the exhaust manifold is subjected to excessivelyhigh temperature and, therefore, the thermal expansion thereof becomesrelatively large because of hot exhaust gases pass therethrough and theexhaust manifold is not cooled. On the other hand, since the rotorhousing is continuously cooled throughout various operating conditionsof the engine, the temperature of the rotor housing does not increasebeyond a predetermined level and, accordingly, the thermal expansionthereof is relatively small. If, in this instance, the exhaust manifoldis connected to the rotor housing by means of suitable fastener meanssuch as bolts, the connecting portion between the exhaust manifold andthe rotor housing is subjected to high mechanical stresses due todifferent thermal expansions. This problem will be more seriousespecially where a thermal reactor is'mounted on the rotor housingbecause the thermal reactor is very rigid and the temperature thereof isrelatively high due to the thermal reaction of the exhaust gases passingtherethrough.

In order to solve this problem, it has heretofore been proposed toprovide large bores in the exhaust manifold for insertion of mountingbolts so that the exhaust manifold and the rotor housing can slide withrespect to each other'when the difference in thermal expansions becomesgreat. Another expedient which has been proposed is to employ an exhaustmanifold which has low rigidity so that, when the difference in thermalexpansions between the exhaust'manifold and the rotor housing becomesgreat, the exhaust manifold is readily deformed to prevent theconnecting portion between the exhaust manifold and the rotor housingfrom being subjected to high mechanical stresses. Since, however, theexhaust ports are separately formed in different positions of the rotorhousing, the exhaust manifolds or thermal reactors should be mounted onthe rotor housing at different positions so as to communicate with eachexhaust port, thus resulting in a complicated construction.

It is, therefore, an object of the present invention to provide animproved exhaust system for a multi-rotor type rotary internalcombustion engine.

Another object of the present invention is to provide an exhaust systemfor a multi-rotor type rotary internal combustion engine, which exhaustsystem in simplified in construction and economical to manufacture.

According to the present invention, there is provided an exhaust systemfor a multi-rotor type rotary internal combustion engine wherein exhaustpassageways communicating with each exhaust port leading from each rotorexhaust chamber are congregated in one portion of a rotor housing sothat one or more than one exhaust manifold or thermal reactor can beconnected to the exhaust passageways at one position of the rotor hous-These and other features and advantages of the present'invention willbecome more apparent from the following description when taken inconjunction with the accompanying drawings in which like component partsare designated by same reference numerals and "in which:

FIG. 1 is a cross sectional view showing one preferred embodiment of anexhaust system for a rotary internal combustion engine of themulti-rotor type according to the present invention,

FIG. 2 is a cross sectional view showing another preferred embodiment ofan exhaust system for a' rotary internal combustion engine of themulti-rotor type according to'the present invention;

FIG. 3 is a cross sectional view showing still another preferredembodiment of an exhaust system for a rotary internal combustion engineof the multi-rotor type according to the present invention;

FIG. 4 is a cross sectional view showing a further embodiment of anexhaust system for a rotary internal combustion engine of themulti-rotor type according to the present invention; and

FIG. 5 is a cross sectional view showing a still further embodiment ofanexhaust system for a rotary internal combustion engine of themulti-rotor type according to the present invention.

Referring now to the drawings and more particulary to FIG. 1, there isshown in section a two-rotor type rotary internal combustionengine'incorporating the exhaust system according to the presentinvention. The rotary internal combustion engine of thistype includes,as customary, two rotor exhaust chambers 10 and 12 in which rotors arerotatably disposed respectively, though not shown. The rotor chamber 10is defined by side housings 14 and 16 and a central housing 18, whereasthe rotor chamber l2'is defined by side housings l6 and 20 and a centralhousing 22. The housings 14, 16, 18, 20 and 22 form a general rotorhousing as will be described. It should be noted that intake ports ofthe rotor chambers 10 and 12 are herein omitted for the sake ofsimplicity of illustration.

It is an important feature of the present invention that exhaustpassageways communicating with each exhaust port leading from each rotorexhaust chamber are formed to be congregated in one portion of the rotorhousing whereby the exhaust manifold or manifolds can be connected tothe exhaust passageways at one portion of the rotor housing. In theembodiment of FIG. 1, the exhaust passageways 24 and 26 are congregatedin the side housing 16 intervening between the rotor chambers 10 and 12.Theexhaust passageways 24 and 26 communicate with exhaust ports 24a and26a formed in the side housing 16 and opening to the rotor exhaustchambers 10 and 12, respectively. Moreover, the exhaust passageways 24and 26 are joined at their end portions so that an exhaust manifold 28can be connected to the exhaust passageways 24 and 26 at one position ofthe rotor housing. In the embodiment of FIG. 2, the exhaust passageways24 and 26 communicating with exhaust ports 24a and 26a, respectively,are separately formed but congregated in one part of the side housing 16so that exhaust manifolds 28a and 2812 can be connected to the exhaustpassageways 24 and 26 at one part of the side housing 16. The exhaustports 24a and 26a may be formed in the central housings 18 and 22,respectively, so as to open to the rotor exhaust chambers 10 and 12 andcommunicate with the exhaust passageways 24 and 26, respectively, formedin the side housing 16 as seen in FIGS. 3 and 4. In the embodiment ofFIG. 3, the exhaust passageways 24 and 26 are joined at their endportions while, in the embodiment of FIG. 4, the exhaust passageways 24and 26 are separately formed but congregated in the side housing 16 aspreviously mentioned. I

Referring next to FIG. 5, there is shown in section a three-rotor typerotary internal combustion engine incorporating the exhaust systemaccording to the present invention. The rotary internal combustionengine of this kind includes, as customary, first, second and thirdrotary exhaust chambers 30, 32 and 34 in which rotors are rotatablydisposed in a known fashion, though not shown. The first rotor exhaustchamber 30 is defined by side housings 36 and 38 and a central housing40. The second rotor exhaust chamber 32 is defined by side housings 38and 42 and a central housing 44. The third rotor exhaust chamber 34 isdefined by side housings 42 and 46 and a central housings 48. It shouldbe noted that each of intake ports of the first, second and third rotorexhaust chambers 30, 32 and 34 is herein omitted for the sake ofsimplicity of illustration. in this illustrated embodiment, exhaustpassageways 50, 52 and 54 are formed to be congregated in one part ofthe central housing 44 intervening between the adjacent side housings 38and 42. The exhaust passageway 50 communicates through an exhaustpassageway 50 formed in the side housing 38 intervening between therotor exhaust chambers 30 and 32 with an exhaust port 50" formed in thecentral housing 40 intervening between the adjacent side housings 36 and38 and communicating with the first rotor exhaust chamber 30. Theexhaust passageway 52 communicates with the second rotor exhaust chamber32 through an exhaust port 52. The exhaust passageway 54 communicatethrough an exhaust passageway 54 formed in the side housing 42intervening between the rotor exhaust chambers 32 and 34 with an exhaustport 54" formed in the central housing 48 intervening between theadjacent side housings 42 and 46 and communicating with the third rotorexhaust chamber 34. These exhaust passageways 50, 52 and 54 areconnected at one portion of the center housing 44 to exhaust manifoldsor connecting pipes 56, 58 and 60 leading to thermal reactors (notshown), respectively.

It will now be understood from the foregoing description that theexhaust system implementing the present invention has exhaustpassageways which are formed together or congregated in one part of therotor housing whereby exhaust manifolds or thermal reactors can beconnected to the exhaust passageways at one portion of the rotorhousing.

What is claimed is:

1. An exhaust system for a multi-rotor type rotary internal combustionengine having a plurality of housing means defining therein rotorchambers including exhaust chambers having exhaust ports respectively,said exhaust system comprising exhaust passageways formed to becongregated in one portion of one of said housing means andcommunicating with said exhaust ports of said rotor exhaust chambers,and at least one exhaust manifold connected at one portion of said oneof said housing means to said exhaust passageways.

2. An exhaust system as claimed in claim 1, wherein said exhaustpassageways are joined at their end portions in said one of said housingmeans.

3. An exhaust system as claimed in claim 1, wherein said exhaustpassageways are separately formed but congregated in said one of saidhousing means.

1. An exhaust system for a multi-rotor type rotary internal combustionengine having a plurality of housing means defining therein rotorchambers including exhaust chambers having exhaust ports respectively,said exhaust system comprising exhaust passageways formed to becongregated in one portion of one of said housing means andcommunicating with said exhaust ports of said rotor exhaust chambers,and at least one exhaust manifold connected at one portion of said oneof said housing means to said exhaust passageways.
 2. An exhaust systemas claimed in claim 1, wherein said exhaust passageways are joined attheir end portions in said one of said housing means.
 3. An exhaustsystem as claimed in claim 1, wherein said exhaust passageways areseparately formed but congregated in said one of said housing means.